1. Technical Field
The technology disclosed herein relates to a telescoping lens barrel.
2. Background Information
Imaging devices that produce image data about a subject have rapidly gained popularity in recent years. A lens barrel for adjusting the focal distance is mounted in these imaging devices. Examples of known imaging devices include cameras with an integrated lens and those with an interchangeable lens. A lens barrel is built into an integrated type of camera. A camera with an interchangeable lens has a camera body and a lens barrel that can be mounted to the camera body.
A conventional lens barrel is disclosed in Japanese Laid-Open Patent Application 2010-38932, for example. With this lens barrel, the focal distance can be adjusted, or the overall length can be shortened from the imaging state to the retracted state by moving a lens group along the optical axis direction by rotating a cam barrel via a gear train linked to a motor. A clutch mechanism is installed for one of the gears in the gear train, and is designed so that excessive torque will be interrupted, and gear train damage will be prevented, by the clutch mechanism when the lens barrel is dropped, etc., and an external force is exerted in a direction that would rotate the cam barrel. The clutch mechanism is configured so that it acts only in the direction in which the cam barrel rotates from the imaging state to the retracted state.